There are different types of telephone numbers that can be used to place a telephone call depending on the geographical location of the telephone receiving the call. A local number requires the least number of digits in the telephone number and can be used to make a local telephone call. For example, in the United States, a local number is composed of seven digits. Telephone calls to areas of a country outside the local calling area will require an area code in addition to the local number. Telephone calls made between countries require further prefixes to the telephone number, such as an international prefix and a country code.
In today's modern telephone, a telephone number can be stored for easy retrieval (e.g., an address book). The telephone number that is stored can be a local number, long distance number, or international number. Whether this stored telephone number can be successfully used to place a telephone call depends in part of the geographical location of the telephone with the stored telephone number. For example, if a stored telephone number is a local number and the telephone has roamed to a different geographically area of the home country associated with the telephone or to a different country, the stored local telephone number will not work.